1. Field of the Invention
The present invention relates to a method for recording address information on an optical recording medium, an optical recording medium including address information recorded thereon by the same method, and a method for detecting the address information recorded on the optical recording medium.
2. Description of the Related Art
A general recordable optical disc (optical recording medium) such as a DVD-RAM, a DVD-RW (Re-Writable), or a high-density optical recording medium has a recess formed along a track having a spiral or concentric-circle form. The recessed portion is called a groove, and the remaining portion is called a land. There are two methods of recording data on the optical disc. One method is to record data on one of the groove and the land, and the other is to record data on both of them. When the groove is formed, a specific variation is formed in the wall of the groove. During the recording or reproducing operations, the specific variation produces a signal having a specific frequency. Thus, the specific variation is used as auxiliary clock means. The specific variation is called a wobble, and the signal having the specific frequency is called a wobble signal.
Meanwhile, physical address information should be formed in advance on the optical disc. To this end, a CAPA (Complementary Allocated Pit Addressing) method is used for the DVD-RAM, and a land pre-pit addressing method is used for the DVD-RW.
The Land pre-pit addressing method used in the DVD-RW has a problem that the address decoding performance may be lowered depending on the state of the disc and recording/reproducing conditions such as a tilt of the disc.
On the other hand, in the CAPA method, sector-by-sector address information is formed and recorded in the pre-pit form at the head of each of the sectors for the physical addressing operation. The CAPA method has an advantage in that a sector-by-sector addressing operation can be performed, but has a problem that, because the address information is recorded on a sector basis on the data recording region on which real data is to be recorded, the data recording capacity for recording real data is reduced.
In order to overcome the problem of reduction in the data recording capacity, a method for recording physical address on the optical recording medium using a wobble signal carrying the physical address has been proposed. This method is called a wobble addressing method.
As an example of such a wobble addressing method, there is a BPSK (Binary Pulse Shift Keying) wobble addressing method that has been adopted in the high-density optical recording medium.
FIG. 1 is a view showing the format of one error correction block of physical address information that is formed and recorded in the wobble form on the high-density optical recording medium by the BPSK wobble addressing method. As shown in FIG. 1, in the high-density optical recording medium, four addressing operations are performed for one ECC (Error Correction Code) block having a predetermined recording size (e.g., an ECC of 16-sector recording size). That is, the error correction code block of 16-sector recording size is divided into four different ADIP (Address In Pre-Groove) words (ADIP Word #1–#4) of 4-sector recording size, and the addressing operation is performed for each ADIP word. One ADIP word includes 52 ADIP units, and one ADIP unit includes 93 wobble units. An ADIP word synchronous code (ADIP Sync) is expressed at the first ADIP unit of each ADIP word, and physical address information of the error correction code block is expressed by 51 bits at the remaining 51 ADIP units. The ADIP word synchronous code indicates that its subsequent 51 ADIP units are physical address data of the error correction code block, and each ADIP word synchronous code has one kind of predetermined code value.
Accordingly, the BPSK wobble addressing method currently used in the high-density optical recording medium has an advantage in that, because there is no need to form and record address information in a separate pre-pit, differently from the CAPA method, the data recording capacity for recording real data can be prevented from being reduced.
However, in the BPSK wobble addressing method, because the ADIP word synchronous code is formed and recorded on a 4-sector basis, it is possible to perform random access, or data overwrite recording, etc., on an error correction block basis, but it is impossible to perform addressing operation on a sector basis.